Mobile vehicles including aircraft, trains, ships, etc. often provide rest areas for crew when the vehicle is intended for operation over lengthy time periods. Commercial aircraft in particular are required to provide crew rest spaces for aircraft which operate over extended periods of time. Common crew rest areas include bunks, chairs or seats, and lavatories for crew use. Aircraft crew rests are commonly separately provided for flight crew members and for flight attendants. Requirements for both crew rests vary, but components are often interchangeable. A common location on an aircraft for flight attendant crew rest areas is at the aft end of the aircraft, rearward of the aft passenger seating area and above the ceiling of the aft passenger seating area. This location is accessible using staircases and doorways or hatches.
Passenger carrier operators often request retrofit of crew rest areas, including adding to or expanding existing crew rest areas, or adding entirely new and independent crew rest areas. This is done to expand capacity by adding berths, increasing crew comfort and amenity levels by increasing berth dimensions, adding a feature such as a lavatory, or accommodating gender distinctions by adding dividers. It is often difficult to backfit existing vehicles, for example aircraft, with additional crew rest space due to items such as piping, structure, environmental control system ducting, flight control cabling, fire detection systems, stow-bin support structure and center stow-bins, and electrical cabling positioned adjacent to existent crew rest areas or areas where crew rests are desirable. Aircraft crew rests also commonly position passageways on the longitudinal centerline of the aircraft to maximize the usable space. Because the systems noted above and centrally positioned passageways normally use desirable crew rest space, these would all need to be moved to allow retrofitting a typical crew rest.
Another difficulty exists in aircraft, for example, having aft crew rest spaces positioned above the ceiling of passenger areas which are supported using ceiling structure. Because the ceiling structure is commonly optimized for the original crew rest space and weight, extending the crew rest volume, adding weight or adding passageway length can require significant modification to the existing passenger area ceiling design in addition to the impact on system piping, structure and cableways. Retrofitting a modified or new crew rest area as a unitary design is therefore impractical for many passenger vehicle designs.